246 Vines —Proteolytic Enzymes in Plants . 
Pyrus communis. 
The variety of Pear used was the Beurrd Hardi. 
20 grms. of crushed, ripe, pear were placed in each of two bottles 
(40 cc.), filled up with chloroform-water: to No. 1 nothing was 
added : to No. 2 , 0-5 grm. Witte-peptone. 
After 4 hours’ digestion, No. 2 gave a faint tryptophane-reaction; 
No. 1, no reaction : after 24 hours’ digestion, No. 2 gave a distinct 
reaction ; and after 48 hours, a marked reaction : No. 1 gave no 
reaction. 
Citrus Aurantium. 
I found that whereas the rind acts on Witte-peptone, the juice 
of the Orange is without effect. 
In each of two bottles (45 cc.) were placed 5 grms. of orange- 
peel : both were filled with 50 % chloroform-water, and to the one 
(No. 2) 0-3 grm. of Witte-peptone was added. In each of two other 
similar bottles (3, 4) were placed 20 cc. of juice, and they were filled 
up with chloroform- water : to No. 4, 0-3 grm. of Witte-peptone was 
added. 
After 24 hours’ digestion, No. 1 gave a faint tryptophane-reaction ; 
No. 2, a strong reaction; No. 3, no reaction; No. 4, a scarcely 
perceptible reaction. 
Viiis vinifera. 
55 cc. of juice and pulp of some ripe White Grapes (hothouse) 
were placed in each of two bottles, Nos. 1 and 2 ; the material in 
No. 2 had been previously boiled: to each, 35 cc. of chloroform- 
water were added, and 0*5 grm. of Witte-peptone. 
After 22 hours’ digestion, No. 1 gave a marked tryptophane-reaction; 
No. 2, no reaction. 
Similar, but less striking results, were given with quite ripe Black 
Grapes. 
Laticiferous Plants. 
In view of the fact that the latex of the Papaw ( Carica 
Papaya) and that of the Fig ( Ficus Carica) are known to 
contain proteases, I tried a few experiments with other latici- 
ferous plants. 
